ISC 2019 Physics Question Paper for Class 12

About this paper

This is ISC Class 12 Physics Paper 1 (Theory), set by CISCE for the 2019 board examination (paper code 861A). It carries 70 marks, runs for three hours plus fifteen minutes of reading time, and has 22 compulsory questions in four sections. Section A is a twelve-mark question with five multiple-choice items and seven very short answers; Sections B and C have internal choices in two questions each, and every five-mark question in Section D has an internal choice. Questions range from electrostatics and AC circuits to optics, atoms and nuclei, semiconductors and frequency modulation. A short list of physical constants is printed at the end, and a simple scientific calculator is allowed. This copy has the questions only.

Exam

ISC Class 12

Subject

Physics

Year

2019

Paper code

861A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

22

Pages

7

Answers included

No, questions only

Paper pattern

• Section A

  12 marks

  Question 1: 5 multiple-choice and 7 very short answer parts, one mark each

• Section B

  22 marks

  Questions 2–12, two marks each; internal choice in two questions

• Section C

  21 marks

  Questions 13–19, three marks each; internal choice in two questions

• Section D

  15 marks

  Questions 20–22, long answers of five marks each, each with an internal choice

Topics covered

• Electrostatics and electric dipole
• Capacitors
• Wheatstone bridge and potentiometer
• Moving charges and magnetism
• Alternating current and transformers
• Electromagnetic waves
• Ray optics, prisms and lenses
• Wave optics and Young's double slit experiment
• Photoelectric effect
• Atoms, nuclei and radioactivity
• Semiconductors, rectifiers and logic gates
• Frequency modulation

Questions from this paper

1. Obtain an expression for the electric potential V at a point in the end-on (axial) position of an electric dipole.
2. A transformer is used to step up an alternating emf of 200 V to 440 V. If the primary coil has 1000 turns, calculate the number of turns in the secondary coil.
3. The deviations produced in violet, yellow and red light by crown glass are 3.75°, 3.25° and 2.86° respectively. Calculate the dispersive power of the crown glass.
4. The half-life of radium is 1550 years. Calculate its disintegration constant (λ).
5. Calculate the focal length of a convex lens whose surfaces have radii of curvature of 10 cm and 15 cm and whose refractive index is 1.5.
6. Define frequency modulation and state one advantage of frequency modulation (FM) over amplitude modulation (AM).